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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

The influence of compost physical parameters on microbial oxygen uptake

Mohajer, Ardavan. January 1900 (has links)
Thesis (M.Sc.). / Written for the Dept. of Bioresource Engineering. Title from title page of PDF (viewed 2009/06/29). Includes bibliographical references.
2

Spatial-temporal influence of integrated multi-trophic aquaculture-derived organic effluent on adjacent marine communities

Weldrick, Christine Kim 17 October 2011 (has links)
Aquaculture facilities have been demonstrated to emit massive quantities of waste that incorporates in to the surrounding water column, effectively altering patterns and processes of nearby marine communities. Given that products from aquaculture is heavily relied upon to meet global fisheries demands, understanding its effects is essential to inventing less harmful practices. This research examines one such facility located in Kyuquot, British Columbia. The purpose of this thesis is to spatially and temporally measure the degree and magnitude of integrated multi-trophic aquaculture (IMTA)-derived organic waste as a potential subsidy to adjacent marine communities. Stable carbon and nitrogen isotopes analysis was applied to intended extractive organisms (sablefish Anoplopoma fimbria, Pacific scallops Patinopectin caurinus, blue mussels Mytilus edulis, sea urchin Strongylocentrotus franciscanus, sea cucumber Parastichopus californicus, kelp Saccharina latissima), epibiont biofouling species (brooding transparent tunicates Corella inflata, hairy tunicate Boltenia villosa, broadbase tunicates Cnemidocarpa finmarkiensis) as well as fish feed and sablefish faeces. Stable isotopes of blue mussels and brooding transparent tunicates sampled from both the IMTA and a reference site were compared in order to examine spatial influence of IMTA-derived waste. IMTA site sampled mussels exhibited the most enriched and least variable values among all four sample groups. Brooding transparent tunicates exhibited the most isotopic variability which demonstrates that IMTA-derived waste is not among the most important food source available. This is corroborated by the three-source mixing model results. Only sablefish isotopic signatures were measured to be more enriched than those of fish feed and fish faeces. Isotopic mixing models were employed to all IMTA samples and found that IMTA effluent signatures were proportionately higher in their diets than averaged marine particulate organic matter (POM) signatures taken from the literature. Mixing model results also showed IMTA effluent to be proportionately less than marine POM. Circular statistical results did not demonstrate particular directional change for all IMTA sampled isotopic signatures which could be due to the consistent nature of available fish feed throughout the year and/or perhaps feeding choice changes constantly. Further examination into the monthly physical properties of this region (eg. rainfall, irradiance) as well as measurements of marine POM signatures would greatly compliment these results and are recommended for future study. / Graduate
3

Enhancement of Anaerobic Digestion of Organic Fraction of Municipal Solid Waste by Microwave Pretreatment

Shahriari Zavareh, Haleh 03 October 2011 (has links)
This study evaluates the enhancement of anaerobic digestion (AD) of the organic fraction of municipal solid waste (OFMSW) by microwave pretreatment (MW) at high temperatures (115, 145 and 175°C). The highest level of solubilization was achieved at 175ºC, with a supplemental water addition of 30% (SWA30). Pretreatments combining two modalities; MW heating in presence or absence of hydrogen peroxide (H2O2) was also investigated. Biochemical methane potential (BMP) tests were conducted on the whole OFMSW, as well as on the liquid fractions. The whole OFMSW pretreated at 115 and 145 ºC showed little improvement in biogas production over control. When pretreated at 175 ºC, biogas production decreased due to formation of refractory compounds, inhibiting digestion. For the liquid fraction of OFMSW, the effect of pretreatment on the cumulative biogas production (CBP) was more pronounced for supplemental water addition of 20% (SWA20) at 145 ºC. Combining MW and H2O2 modalities did not have a positive impact on OFMSW stabilization and enhanced biogas production. Based on the BMP assay results, the effects of MW pretreatment (145 ºC) on the AD of OFMSW (SWA20) were further evaluated in single and dual stage semi-continuous digesters at hydraulic retention times (HRTs) of 20, 15, 12 and 9 days. Overall, MW pretreatment did not enhance the AD of the whole waste at the HRTs tested. However, the use of a dual stage reactor digesting non pretreated whole OFMSW had the best performance with the shortest HRT of 9 days. Conversely, for free liquid after pretreatment in two stage reactors at 20 day HRT methane production was tripled. In general, the performance of the dual stage digesters surpassed that of the single stage reactors. Cyclic BMP assays indicated that using an appropriate fraction of recycled effluent leachate can be implemented without negatively effecting methanogenic activity and biogas production. Based on the results obtained in this study, digestion of OFMSW by dual stage reactors without pretreatment appears to provide the best potential for waste stabilization in terms of biogas production and yield, process stability and volumetric loading rates.
4

Enhancement of Anaerobic Digestion of Organic Fraction of Municipal Solid Waste by Microwave Pretreatment

Shahriari Zavareh, Haleh 03 October 2011 (has links)
This study evaluates the enhancement of anaerobic digestion (AD) of the organic fraction of municipal solid waste (OFMSW) by microwave pretreatment (MW) at high temperatures (115, 145 and 175°C). The highest level of solubilization was achieved at 175ºC, with a supplemental water addition of 30% (SWA30). Pretreatments combining two modalities; MW heating in presence or absence of hydrogen peroxide (H2O2) was also investigated. Biochemical methane potential (BMP) tests were conducted on the whole OFMSW, as well as on the liquid fractions. The whole OFMSW pretreated at 115 and 145 ºC showed little improvement in biogas production over control. When pretreated at 175 ºC, biogas production decreased due to formation of refractory compounds, inhibiting digestion. For the liquid fraction of OFMSW, the effect of pretreatment on the cumulative biogas production (CBP) was more pronounced for supplemental water addition of 20% (SWA20) at 145 ºC. Combining MW and H2O2 modalities did not have a positive impact on OFMSW stabilization and enhanced biogas production. Based on the BMP assay results, the effects of MW pretreatment (145 ºC) on the AD of OFMSW (SWA20) were further evaluated in single and dual stage semi-continuous digesters at hydraulic retention times (HRTs) of 20, 15, 12 and 9 days. Overall, MW pretreatment did not enhance the AD of the whole waste at the HRTs tested. However, the use of a dual stage reactor digesting non pretreated whole OFMSW had the best performance with the shortest HRT of 9 days. Conversely, for free liquid after pretreatment in two stage reactors at 20 day HRT methane production was tripled. In general, the performance of the dual stage digesters surpassed that of the single stage reactors. Cyclic BMP assays indicated that using an appropriate fraction of recycled effluent leachate can be implemented without negatively effecting methanogenic activity and biogas production. Based on the results obtained in this study, digestion of OFMSW by dual stage reactors without pretreatment appears to provide the best potential for waste stabilization in terms of biogas production and yield, process stability and volumetric loading rates.
5

Enhancing nutrient solubilization from organic waste using the microwave technology

Kenge, Anju A. 11 1900 (has links)
Organic wastes like sewage sludge and dairy manure were subjected to microwave enhanced advanced oxidation process ( MW/H₂0₂-AOP). The MW/H₂O₂-AOP was developed to release nutrients like phosphorus and nitrogen in the soluble form from the organic waste; these nutrients could be further recovered and reused. In the past, this process has been successfully applied to a series of organic waste for the purpose of solubilizing nutrients. The objectives of this research were to: (1) improve the MW/H₂0₂-AOP in terms of nutrient release by determining the different factors that influence the treatment, (2) define the factors affecting the process in their order of significance and (3) check the efficacy of the process on various waste. In the MW/H₂0₂-AOP, the role of mixing was verified, using municipal sewage sludge (aerobic and anaerobic). It was speculated that mixing the samples during the process would facilitate uniform heating and thus promote more nutrient release. At a microwave temperature of 80 °C, heating time of 5 minutes and hydrogen peroxide dosage of 1 mL per 1% of total solids, the results showed that mixed samples gave a higher nutrient solubilization compared to the unmixed. Subsequently, mixing and solids concentration were incorporated in a screening design with the other proven important factors viz., microwave temperature and hydrogen peroxide dosage. The results showed that microwave temperature and hydrogen peroxide dosage were the most significant factors for the release of orthophosphate, ammonia and soluble chemical oxygen demand. Preliminary experiments treating anaerobic sludge using MW/H₂O₂-AOP showed a decrease in orthophosphate concentration below the initial untreated value while for ammonia and volatile fatty acids the concentrations remained same as the initial. In this case, the set microwave temperature was 80 °C with 5 minutes heating and hydrogen peroxide dosage of 1 mL per 1% total solids at pH 7. To investigate this behavior, anaerobic sludge was treated at two pH conditions (7.8 and 4) at microwave temperatures ranging from 80 to 160 °C with hydrogen peroxide dosage of lmL per 1% total solids for 5 minutes. The results showed that acid addition helped in the destruction of sludge solids and release of nutrients. TheMW/H₂0₂-AOP was used to treat separated solid dairy manure. Solid dairy manure with total solids 1.6% was subjected to microwave temperature of 120 °C for 10 minutes with a hydrogen peroxide dosage of 2 mL per 1% total solids at three pH conditions (3.5, 7.3 and 12). Only at pH 3.5, substantial quantity of orthophosphate, ammonia, soluble chemical oxygen demands and volatile fatty acids could be released. Further, a screening experiment was designed including microwave temperature, hydrogen peroxide dosage and heating time, to determine the factors most affecting nutrient solubilization from solid dairy manure. Hydrogen peroxide dosage and temperature were important factors in orthophosphate release while microwave temperature and heating time were important in the release of ammonia and volatile fatty acids. The results clearly define the efficacy of the MW/H₂0₂-AOP on various organic waste as well as the conditions under which the treatment can be optimized.
6

Enhancing nutrient solubilization from organic waste using the microwave technology

Kenge, Anju A. 11 1900 (has links)
Organic wastes like sewage sludge and dairy manure were subjected to microwave enhanced advanced oxidation process ( MW/H₂0₂-AOP). The MW/H₂O₂-AOP was developed to release nutrients like phosphorus and nitrogen in the soluble form from the organic waste; these nutrients could be further recovered and reused. In the past, this process has been successfully applied to a series of organic waste for the purpose of solubilizing nutrients. The objectives of this research were to: (1) improve the MW/H₂0₂-AOP in terms of nutrient release by determining the different factors that influence the treatment, (2) define the factors affecting the process in their order of significance and (3) check the efficacy of the process on various waste. In the MW/H₂0₂-AOP, the role of mixing was verified, using municipal sewage sludge (aerobic and anaerobic). It was speculated that mixing the samples during the process would facilitate uniform heating and thus promote more nutrient release. At a microwave temperature of 80 °C, heating time of 5 minutes and hydrogen peroxide dosage of 1 mL per 1% of total solids, the results showed that mixed samples gave a higher nutrient solubilization compared to the unmixed. Subsequently, mixing and solids concentration were incorporated in a screening design with the other proven important factors viz., microwave temperature and hydrogen peroxide dosage. The results showed that microwave temperature and hydrogen peroxide dosage were the most significant factors for the release of orthophosphate, ammonia and soluble chemical oxygen demand. Preliminary experiments treating anaerobic sludge using MW/H₂O₂-AOP showed a decrease in orthophosphate concentration below the initial untreated value while for ammonia and volatile fatty acids the concentrations remained same as the initial. In this case, the set microwave temperature was 80 °C with 5 minutes heating and hydrogen peroxide dosage of 1 mL per 1% total solids at pH 7. To investigate this behavior, anaerobic sludge was treated at two pH conditions (7.8 and 4) at microwave temperatures ranging from 80 to 160 °C with hydrogen peroxide dosage of lmL per 1% total solids for 5 minutes. The results showed that acid addition helped in the destruction of sludge solids and release of nutrients. TheMW/H₂0₂-AOP was used to treat separated solid dairy manure. Solid dairy manure with total solids 1.6% was subjected to microwave temperature of 120 °C for 10 minutes with a hydrogen peroxide dosage of 2 mL per 1% total solids at three pH conditions (3.5, 7.3 and 12). Only at pH 3.5, substantial quantity of orthophosphate, ammonia, soluble chemical oxygen demands and volatile fatty acids could be released. Further, a screening experiment was designed including microwave temperature, hydrogen peroxide dosage and heating time, to determine the factors most affecting nutrient solubilization from solid dairy manure. Hydrogen peroxide dosage and temperature were important factors in orthophosphate release while microwave temperature and heating time were important in the release of ammonia and volatile fatty acids. The results clearly define the efficacy of the MW/H₂0₂-AOP on various organic waste as well as the conditions under which the treatment can be optimized.
7

An experimental study of air scour in biological treatment

Amini-Rad, Hassan January 1993 (has links)
No description available.
8

Enhancement of Anaerobic Digestion of Organic Fraction of Municipal Solid Waste by Microwave Pretreatment

Shahriari Zavareh, Haleh 03 October 2011 (has links)
This study evaluates the enhancement of anaerobic digestion (AD) of the organic fraction of municipal solid waste (OFMSW) by microwave pretreatment (MW) at high temperatures (115, 145 and 175°C). The highest level of solubilization was achieved at 175ºC, with a supplemental water addition of 30% (SWA30). Pretreatments combining two modalities; MW heating in presence or absence of hydrogen peroxide (H2O2) was also investigated. Biochemical methane potential (BMP) tests were conducted on the whole OFMSW, as well as on the liquid fractions. The whole OFMSW pretreated at 115 and 145 ºC showed little improvement in biogas production over control. When pretreated at 175 ºC, biogas production decreased due to formation of refractory compounds, inhibiting digestion. For the liquid fraction of OFMSW, the effect of pretreatment on the cumulative biogas production (CBP) was more pronounced for supplemental water addition of 20% (SWA20) at 145 ºC. Combining MW and H2O2 modalities did not have a positive impact on OFMSW stabilization and enhanced biogas production. Based on the BMP assay results, the effects of MW pretreatment (145 ºC) on the AD of OFMSW (SWA20) were further evaluated in single and dual stage semi-continuous digesters at hydraulic retention times (HRTs) of 20, 15, 12 and 9 days. Overall, MW pretreatment did not enhance the AD of the whole waste at the HRTs tested. However, the use of a dual stage reactor digesting non pretreated whole OFMSW had the best performance with the shortest HRT of 9 days. Conversely, for free liquid after pretreatment in two stage reactors at 20 day HRT methane production was tripled. In general, the performance of the dual stage digesters surpassed that of the single stage reactors. Cyclic BMP assays indicated that using an appropriate fraction of recycled effluent leachate can be implemented without negatively effecting methanogenic activity and biogas production. Based on the results obtained in this study, digestion of OFMSW by dual stage reactors without pretreatment appears to provide the best potential for waste stabilization in terms of biogas production and yield, process stability and volumetric loading rates.
9

Facilitating Phosphorus Recovery Through Improved Waste Management

January 2016 (has links)
abstract: Phosphorus (P) is an essential resource for global food security, but global supplies are limited and demand is growing. Demand reductions are critical for achieving P sustainability, but recovery and re-use is also required. Wastewater treatment plants and livestock manures receive considerable attention for their P content, but municipal organic waste is another important source of P to address. Previous research identified the importance of diverting this waste stream from landfills for recovering P, but little has been done to identify the collection and processing mechanisms required, or address the existing economic barriers. In my research, I conducted a current state assessment of organic waste management by creating case studies in Phoenix, Arizona and New Delhi, India, and surveyed biomass energy facilities throughout the United States. With participation from waste management professionals I also envisioned an organic waste management system that contributes to sustainable P while improving environmental, social, and economic outcomes. The results of my research indicated a number of important leverage points, including landfill fees, diversion mandates for organic waste, and renewable energy credits. Source separation of organic waste improves the range of uses, decreases processing costs, and facilitates P recovery, while creating jobs and contributing to a circular economy. Food is a significant component of the waste stream, and edible food is best diverted to food banks, while scraps are best given to livestock. Biomass energy systems produce multiple revenue streams, have high processing capacities, and concentrate P and other minerals to a greater extent than composting. Using recovered P in urban agriculture and native landscaping results in additional benefits to social-ecological systems by improving food security, reducing the urban heat island effect, sequestering carbon, and enhancing urban ecosystems. / Dissertation/Thesis / Biomass Energy Facility Spreadsheet / Anaerobic Digester Facility Spreadsheet / Raw Data from Biomass Survey / Individual Responses from Biomass Survey / Raw notes from India case studies / Doctoral Dissertation Sustainability 2016
10

Isolamento, seleção e estudo de microrganismos ligninoliticos degradadores de chorume / Isolation, selection and study of microorganisms ligninolytic decomposers of manure

Bavutti, Hamilton Roberto Fortes 01 August 2018 (has links)
Orientador : Lucia Regina Durrant / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-01T23:55:15Z (GMT). No. of bitstreams: 1 Bavutti_HamiltonRobertoFortes_D.pdf: 34939085 bytes, checksum: 2fbad9e1098a28b05a4e68c56a2847ef (MD5) Previous issue date: 2002 / Resumo: O objetivo deste trabalho foi estabelecer parâmetros para a degradação biológica de várias amostras de chorume obtidas de um aterro sanitário da região metropolitana de Campinas, determinar os tipos de microrganismos mais comumente encontrados nestas amostras e estudar o metabolismo dos mesmos. Inicialmente 323 linhagens foram isoladas utilizando-se o meio de cultura R2A. Estas linhagens foram testadas quanto a sua resistência frente a compostos tóxicos e crescimento sobre lignina. Foram realizados 8 experimentos mudando-se as características de cultivo e alguns parâmetros foram observados, tais como degradação de fenol, degradação de compostos tóxicos presentes no chorume, redução da demanda química de oxigênio (OQO) e diminuição da cor. 00 total delinhagens analisadas, 4 linhagens fúngicas mostraram-se mais adequadas para conseguir degradar os compostos altamente poluentes presentes no chorume. As linhagens 74, 100, 108 e 184 foram testadas e a linhagem 184 destacou-se como sendo a melhor em quase todos os testes. Uma linhagem bacteriana (254) também atingiu bons resultados em alguns testes e merece outros estudos. O máximo de redução da OQO foi conseguido pela linhagem 184 nos experimentos IV (51,8%) e V (50,4%). As melhores taxas de degradação do fenol também foram atingidos pela linhagem 184 nos mesmos experimentos (72,9% e 63,7% respectivamente). A linhagem 100 também apresentou bons resultados e reduziu a OQO em 36,8% no experimento 111e 38,6% no experimento IV. Quanto à degradação do fenol, a mesma linhagem conseguiu taxas de degradação de 50,1 % no experimento IV. O chorume não autoclavado serviu melhor aos experimentos, bem como a adição de glicose e extrato de leveduras como nutrientes de crescimento / Abstract: The purpose of this work was to stablish parameters for the biological degradation of several leachate samples from a Campinas region's municipal sanitary landfill, to determine the kínd of microorganisms commonly found on these samples and to study their metabolism. Initally 323 strains were isolated using R2A medium. These strains were tested to toxical compounds resistance and ability to growth on lignin. Degradation of total leachate compounds, phenol degradation, DOO reduction and colour reduction were analysed in eíght different culture conditions. Four (4) fungal strains were more prepared to degrade the highly toxical leachate compounds. Strains 74, 100, 108 and 184 were tested and the strain 184 appeared to be the best in almost ali the conditions. One bacterial strain (254) also showed good results in some tests and deserves a detailed study. The maximum of DOO reduction was reached by the 184 strain in the experiments IV (51,8%) and V (50,4%). The best rates of phenol degradation were also reached by the strain 184 in the same experiments (72,9% and 63,7% respectiveUy). Strain 100 also presented good results and reduced the DOO around 36,8% in experiment 111and 38,6% in experiment IV. The same strain degradaded about 50,1% of phenol in the experiment IV. Non sterilized leachate added with glucose and yeast extract was better metabolized compared to non-added and sterilized leachate / Doutorado / Doutor em Ciência de Alimentos

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